MIT professor Kerry Emanuel is among a rare breed of conservative scientists who are sounding the alarm for climate change and criticizing Republicans' 'agenda of denial' and 'anti-science stance.'

Reporting from Cambridge, Mass. — According to the conventional wisdom that liberals accept climate change and conservatives don't, Kerry Emanuel is an oxymoron.

Emanuel sees himself as a conservative. He believes marriage is between a man and a woman. He backs a strong military. He almost always votes Republican and admires Ronald Reagan.

Emanuel is also a highly regarded professor of atmospheric science at MIT. And based on his work on hurricanes and the research of his peers, Emanuel has concluded that the scientific data show a powerful link between greenhouse gas emissions and climate change.

"There was never a light-bulb moment but a gradual realization based on the evidence," Emanuel said. "I became convinced by the basic physics and by the better and better observation of the climate that it was changing and it was a risk that had to be considered."

As a politically conservative climatologist who accepts the broad scientific consensus on global warming, Emanuel occupies a position shared by only a few scientists.

In much the same role that marriage and abortion played in previous election cycles, denial of climate change has now become a litmus test for the right.

The vast majority of Republicans elected to Congress during the midterm election doubt climate science, and senior congressional conservatives — Republican and Democrat — have vowed to fight Obama administration efforts to curtail greenhouse gas emissions.

That's why scientists such as Emanuel rattle the political pigeonholes. Some are speaking out, using their expertise and conservative credentials to challenge what many researchers consider widespread distortions about climate change.

Texas Tech atmospheric scientist Katharine Hayhoe is an evangelical Christian who travels widely talking to conservative audiences and wrote a book with her husband, a pastor and former climate change denier, explaining climate change to skeptics.

A physicist by training, John Cook is an evangelical Christian who runs the website skepticalscience.com, which seeks to debunk climate change deniers' arguments. Barry Bickmore is a Mormon, a professor of geochemistry at Brigham Young University and the blogger behind Anti-Climate Change Extremism in Utah, where he recently rebuked Sen. Orrin G. Hatch (R-Utah) for his climate views and posted editorials mentioning his Republican affiliation.

Emanuel waded into the fray early last year. He wrote a letter to the Wall Street Journal criticizing a friend and colleague for dismissing the evidence of climate change and clinging "to the agenda of denial." Then Emanuel added his name to the Climate Science Rapid Response Team, a website run by scientists to provide accurate information from top researchers in climate-related fields.

"I've always rebelled against the thinking that ideology can trump fact," said Emanuel, 55. "The people who call themselves conservative these days aren't conservative by my definition. I think they're quite radical."

Paradoxically, over the last 40 years, it was conservative Republican administrations that pushed through the creation of the Environmental Protection Agency and the signing of the Endangered Species Act and the Clean Air Act.

But today, most conservatives have lined up against scientists — and transformed what started out as a technical issue into one dominated by ideology and sometimes religion.

"Kerry is a self-avowed conservative," said Michael Mann, a climate scientist who called Emanuel "a leading light" in the field. "But that has no bearing on his view that human-caused climate change is a reality — that, after all, is a scientific issue, not a political issue," he said.

A 2009 poll by the Pew Research Center for the People & the Press found that only 6% of scientists called themselves Republicans, compared with 55% who identified themselves as Democrats.

A separate October 2009 Pew survey showed a marked decline from 18 months earlier in the number of people who accept global warming, with only a third of Republican respondents saying they saw solid evidence of climate change, the lowest percentage among any partisan group.

"Conservatives tend to gravitate to skepticism because conservatives are inherently suspicious of an expanding government taking more and more of their money and liberty," wrote James M. Taylor, senior fellow in environment policy at the Heartland Institute, a conservative think tank in Chicago.

"On the other hand, liberals tend to gravitate to alarmism because they have little fear of an expansive government and tend to welcome government replacing private individuals or corporations as key drivers of the global economy," he said.

Emanuel dislikes applying the word "skeptic" to those who deny climate change. He says all scientists are skeptical; that's the nature of the field. His own innate skepticism meant that it took him longer than his colleagues to be persuaded of climate change, Emanuel said.